Timing properties of Ce-doped YAP and LuYAP scintillation crystals

The timing performance of radiation detectors based on Ce-doped perovskites YAlO₃ (YAP) and (Lu${}_{\mathrm{1-x}}$-$Y_x$)AlO₃ (LuYAP) coupled with near-UV sensitive silicon photomultipliers (NUV-HD SiPMs) have been compared in coincidence time resolution (CTR) experiments. The single-detector time resolution full width at half maximum (FWHM) of YAP was found to be 169 ps, i.e., by a factor of two better than that observed earlier with photomultiplier readout. Introduction of lutetium into YAP structure deteriorates the time resolution to 286 ps and 309 ps for a Lu/Y atomic ratio of 1:1 and 0.7:0.3, respectively. The study of the dynamics of Ce${}^{3+}$excited state population after selective optical excitation with short (200 fs) pulses by using the differential absorption technique in pump and probe configuration evidenced the importance of electron trapping, which is enhanced by antisite Lu${}_{\mathrm{Al}}$ defects having favorable conditions to occur in LuAP.